Compress PDF
Shrink a PDF to fit an email or upload limit. Choose strong compression for scanned and photo-heavy PDFs, or a lossless optimisation that keeps text selectable. You see the exact size saved before downloading.
Runs in your browser
How to use
- Drop a PDF.
- Choose strong or lossless compression (and a level).
- Click Compress PDF.
- Check the new size and download.
How it works
Strong compression renders every page as an image at 80–150 DPI and stores it as JPEG, then rebuilds the PDF. It dramatically shrinks scans and PDFs full of high-resolution photos, but text becomes part of the image — it can't be selected or searched anymore. Use it for scans and visual documents, not for contracts you'll need to copy text from.
Lossless optimisation rewrites the file with compressed object streams without touching page content; gains are modest (typically 0–15%). If a method can't make your file smaller, we tell you rather than giving you a bigger file.
Files are processed in your browser with the open-source pdf-lib and pdf.js libraries — they are never uploaded.
Examples
- Scanned contract
- A 24 MB, 12-page colour scan → about 2 MB at the recommended level.
- Exported report
- A text-heavy 800 KB report is usually already compact.
- Photo-heavy slide deck
- A 30 MB PDF exported from slides with full-page photos typically drops to 3–5 MB at the recommended level, with no visible change on screen.
Common uses
- Email attachments with size limits
- Online forms (visa, university, government)
- Archiving scans
Privacy & security
This tool runs entirely in your browser. Your files and text are never uploaded to our servers — processing happens on your device and results are created locally. How each tool handles files
Frequently asked questions
Why does my text become unselectable with strong compression?
Pages are turned into images to shrink them. Use lossless mode if you need selectable text.
Why didn't my PDF get smaller?
Text-based PDFs are usually already compact; most size in PDFs comes from images.
Which level should I choose?
Start with the recommended level and check the result. Lossless keeps text selectable and is the only safe choice for contracts and forms; strong compression is for scans and photo-heavy files where readability on screen is all that matters.
How do I get under a 5 MB email limit?
Try the recommended level first. If it isn't enough, split the document and send it in two parts, or share a link instead — pushing the quality lower quickly makes scanned text hard to read.
Will the pages still print correctly?
Yes, but a page rendered at 80–150 DPI is meant for screens. For printing, keep the lossless option or the original file: printers resolve 300 DPI and the difference shows.
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